Air sampling devices

Various air sampling devices

1. AIR SAMPLING DEVICES

2. AIR SAMPLING DEVICES

3. PRELIMINARY CONCERNS FOR
CONDUCTING AIR SAMPLING
•Considerthepossiblecharacteristicsandconditionsoftheaerosol,
includingsizerangeofparticles,relativeamountofinertmaterial,
concentrationofmicroorganisms,andenvironmentalfactors.
•Determinethetypeofsamplinginstruments,samplingtime,and
durationofthesamplingprogram.
•Determinethenumberofsamplestobetaken.

4. SLIT SAMPLER
•TheSlitsamplerwasdevelopedbyBourdillon(1941).
•Inthisarotatingpetridishcontainingsuitablenutrientagarmediaisplacedunderaslit
throughwhichairisdrawn.
•Samplingisdoneforshorttimetoavoidtheinterferenceofgrowthofonecolonywith
another.Slitsamplerisoneofseveralsamplingmethodsusedforquantitationofbiological
aerosols.
•Inthismethod,particlesfromtheairareimpingeddirectlyonarotatingagarplate,theplateis
incubated,andthecoloniesthatdevelopfromthebacteria-ladenparticlesarecounted.
•Highlyefficientdeviceandcancollectupto95%ofthewaterdropletparticlessprayedinto
air.
•Evenrespiratorysecretiondropletnucleiof0.2μmdiametercanbecollectedinlargenumbers.

5. •Aninexpensiveslitsamplerforcollectingmicroorganismshasbeendesigned
whichutilizesa150x20mmcultureplatepossessing2.2timestheareaofthe
standardPetridish.
•Thisincreasedareapermitscollectionofamuchgreaternumberoforganisms
withthistypeofsamplerandpreventsdryingoutofthemedia.
•Asimpletimingdeviceisincorporatedinthedesignofthesamplerwhich
permitsrotationattherateof1revolutionperhour,andrendersanaccurate
timeconcentrationrelationship.
SLIT SAMPLER

6. SLIT SAMPLER

7. SLIT SAMPLER
❖Theslitopeningmaybesetatvariouswidths,bymeansoftworecessed
screwswhichholdthetwometalplatesontheslittubeinplace.
❖Thesamplingboxisacylindricalcontainerhousingtheculturedishandthe
agarplateholder.
❖Thedishcontainingtheimpingementmediaiscommerciallyavailable.
❖Theagarplateholderisametallicplatformcontainingfourclipswhich
holdtheplatesecurelyinposition.

8. ❖Thedriveshaftisballbearingsuspendedandismountedtotheintervaltimerby
meansofanadapter.
❖Thefunctionoftheintervaltimeristoprovideuniformrotationoftheplatefora
periodof1hour.
❖Thehousingfortheintervaltimerismadegas-tightbymeansofan"O"ringplacedin
agrooveonthebottomexteriorsurfaceofthesamplingbox.
❖Whentheintervaltimerhousingisscrewedinpositionagas-tightsealissecured.The
volumeandrateofairflowaredeterminedbyacalibratedflowmeter.
SLIT SAMPLER

9. It draws in air from the environment at a fixed rate and causes the suspended particles to fall on the
surface of the agar plate.

10. USEOFSLITSAMPLERFOR
AIRSURVEILLANCE
•Slitsamplerisoneofseveral
samplingmethodsusedfor
quantitationofbiologicalaerosols.
•Theparticlesfromtheairdirectly
settleonarotatingagarplate,the
plateisincubated,andthecolonies
thatdevelopfromthebacteria-laden
particlesarecounted.

11. GRAVITYSLIDE
•ThegravityslidewasusedbyBlackley(1873).
•Theyarecheap,simpleandcanoperatecontinuously.
•Buttheyfailtoestimatetheairsporaquantitativelyandgivesadistortedpictureofairspora,
becausetheypreferentiallyselectthelargerparticles.
•TocorrectthisdistortionScheppegrell(1922)triedtocalculatethevolumetricconcentration
usingaformulabasedonparticlediameterwhichwaslatercorrectedbyCocke(1937)to
particleradius.
•Butinspiteofthesedefectsitiswidelyusedbyaerobiologistsandhascontributedmuch
knowledgetotheairspora.

12. •Air sampling cassette/ slide is designed for the rapid collection of a wide range of airborne aerosols including
mold spores, pollen, insect parts.
•It collects both viable and non-viable sample specimens.
•After sampling is completed, the cassettes are sent to a laboratory, where the slides are removed and direct
microscopic analysis can be immediately performed.
GRAVITYSLIDE
•Bioaerosols:moldspores,pollen,insectparts,skincellfragments
•Fibers:asbestos,fiberglass,cellulose,clothingfibers,synthetics
•InorganicParticulate:ceramic,flyash,copytoner,oildroplets,paint
•OtherOpaqueParticulates:productsofcombustion,rust,salts

13. •Particulateladenairisacceleratedasitisdrawnthrough
thecassettestaperedinletslitanddirectedtowardsasmall
slidecontainingthecollectionmedia,wheretheparticles
becomeimpacted,andtheairflowcontinuesouttheexit
orifice.
•Theadhesivenatureofthecollectionmediapreventsthe
collectedparticulatefromblurringorbeingwashedoff
duringthelaboratorystainingprocess,andeliminates
samplelossfromvibrationduringhandlingandshipment.
•Aftersamplingiscompleted,thecassettesaresenttoa
laboratory,wheretheslidesareremovedanddirect
microscopicanalysiscanbeimmediatelyperformed.
•Thecollectionmediaiscompatiblewithawiderangeof
biologicalstainsandrefractiveindexoils,allowingdirect
quantitativeanalysisoforganicandinorganicparticulate.
GRAVITYSLIDE

14. ➢ThiswasfirstusedbyRempe(1937)fortrappingairbornepollen.
➢Itisawindimpactionsamplerusedforroutineaerobiologicalsurveyandfoundtobevery
inexpensiveandeffectiveforobtainingmaximuminformationontheairbornemicrobiota.
➢Theverticalcylinderexposingunitconsistsofcylinderholderandashelterwhichisa
modifieddesignoftheDurhamtypeshelter.
➢Thishasan"L"shapedsteelanglewithacylinderholderdevicebelowandtheunitis
coveredontopbyacircularaluminiumplatewhichactsasashield.
➢Thecylinderholdingdeviceisa5cmlongirontubewhichisprovidedwithascrewonone
sidenearitsupperendtoholdthecylinderfirmlyinaverticalposition.
➢Sterileandcleanglassrodsof13cmlengthand0.53cmdiameterwereusedinthisstudy.
VERTICAL CYLINDER

15. VERTICAL CYLINDER

16. ❖Sporescountedintheareascannedcanbethenconvertedtonumberpersquarecentimeterfor
comparisonwithothercatchesoncylindertraps.
❖Theverticaltrapisconvenientandcheapbutthemaindrawbackisthatitcatchesanegligible
amountofsporeinstillairandsmallsporesatordinarywindspeedandsochangesincatchoccurs
withalterationinwindspeed.
VERTICAL CYLINDER

17. HIRST SPORE TRAP
•Hirst-typesporetraps(HTST)isavolumetricimpactionsamplerwhichpermittohave
resultsoftheairfungalsporeloadquickly.
•Withthisdevice,bothviableandnonviablesporesareimpactedonasiliconstrip,then
microscopicallyread,butthesporesarenotcultured.
•Thus,thisdevicemayhaveaninteresttomonitorfungalloadsinairasnogrowingtimeis
needed.
•TheHirstsporetrapisthemostwidelyusedsamplerinaerobiologicalsurveysfor
monitoringfungalpropagulesandpollengrains.
•RecentstudieshavetakenadvantageofthisdevicetoperformDNA-basedstudiesfor
pollenidentification.

18. ✓TheHirstsporetrapwasusedformonitoringnotonlypollenbutalsofungalpropagules
andairbornebacteriabyhigh-throughputsequencing.
✓Detection,monitoring,andcharacterizationofthewidediversityofbiologicalentities
presentintheairaredifficulttasksthatrequiretimeandexpertiseindifferentdisciplines.
✓TheHirstsporetrap(aninstrumentbroadlyemployedinaerobiologicalstudies),todetect
andidentifytheseorganismsbyDNA-basedanalyses.
✓TheresultsshowedaconsistentcollectionofDNAandagoodconcordancewithtraditional
methodsforidentification,suggestingthatthesedevicescanbeusedasatoolfor
continuousmonitoringoftheairbornebiodiversity,improvingtaxonomicresolutionand
characterizationtogether.
HIRST SPORE TRAP

19. •Hirstsporetrapisanautomaticvolumetricsporetraptooperatecontinuously
for24hrinthefield.
•Later,amodifiedtrapthatwouldoperatecontinuouslyforsevendays.
•Samplesarecollectedatanetworkofsitesusingvolumetricsporetrapsthat
areusuallysituatedonflatrooftopsawayfromobstructionsandfromlocal
sourcesofpollen.
•Forworkinplantpathology,trapsaregenerallyplacedwithinorjust
downwindofthecroptodetectinoculumortostudythedispersalofplant
pathogensinthefield.
•Thechoiceofpowersupplyisalsoaconsideration.
•Whenthetrapisrunwithamainssupplywithinreach,anarmouredcablecan
beusedalongwithawaterproofandprotectedconnectiontothetrapplug.
HIRST SPORE TRAP

21. Hirstsporetrap
https://www.youtube.com/watch?v=b5bgHMEdzPw
https://www.youtube.com/watch?v=3_i2ldfYYmM
https://iul-instruments.com/product/spin-air-air-sampler/

22. AIR SAMPLING DEVICES
Dr.M. Sonia Angeline
Assistant Professor
Department of Life Sciences
KRISTU JAYANTI COLLEGE

23. •Therotorodsamplerisacheap,simpleandportableairsampler.
•ItconsistsofaU-shapedmetalrodattachedbyaspindletoabattery-poweredelectricmotor.
•Themotorcausestheuprightarmsofthemetalrodtorotateathighspeed.
•Tousethesampler,theuprightarmsarecoveredwithnarrowstripsofstickytape,sothatanysporesintheair
willimpactontothetapes.
•Thenthetapesareremovedandexaminedmicroscopicallytoidentifythesporesandotherparticlessuchas
pollengrainsintheair.
•Thistypeofsamplerismosteffectivefortrappingrelativelylargeparticles(upwardsofabout7micrometres)such
asthelargerfungalsporesandpollengrains.
ROTOROD SAMPLER

24. •The RotorodSampler is a rotating-arm impactor that recovers airborne particles on two
rapidly moving plastic collector rods.
•The standard method for applying silicone grease to collector rods has been with one's
finger.
•Arelatively high skill level is required, and significant intra preparer variability has been
observed.
•Collector rods were coated with silicone grease by dipping them into a solution consisting of
silicone grease and hexane.
•TheRotorod'scollectionefficiencyappearedtobegreatestatmoderatewindspeeds;lower
efficienciesoccurredatbothlowerandhigherwindspeeds.Maximumchangesincollection
efficiencyrangedfrom29%to39%overthewindspeedsemployed.
ROTOROD SAMPLER

25. ROTOROD SAMPLER
•Models typically used have retracting rods
•Head rotates at 2400 rpm, leading edge of rod coated with silicon grease
•Pollen and spores impacted on greased surface
•Generally operated at 10% sampling time
•Efficient for pollen and spores >10 mm

26. ROTOROD
https://www.youtube.com/watch?v=qobfzn5sW3g

27. ❖Andersen(1958)developedasamplersimilarinprincipletoslitsampler.
❖TheAndersonsamplerisaningeniousdeviceforselectivelytrappingdifferentsizesofparticles
accordingtotheirsize(momentum).
❖Thissamplerconsistsofastackof8metalsectionsthatfittogetherwithringsealstoformanair-
tightcylinder.
❖Eachmetalsectionhasaperforatedbase,andthenumberofperforationsisthesameineach
section,butthesizeoftheseperforationsisprogressivelyreducedfromthetopofthecolumntothe
bottom.
❖Tousethissampler,openagarplatesareplacedbetweeneachmetalsection,restingonthreestuds.
ANDERSONSAMPLER

28. ✓When fully assembled (with an open agar plate between each unit) an electric motor sucks air from the bottom of the unit,
causing spore-laden air to enter at the top and to pass down through the cylinder.
✓Air sucked in at the top of the columntravels at relatively low speed towards the first agar plate, and so only the largest
particles impact onto the agar surface.
✓The air then travels round the edge of the agar plate and through the perforations to the second agar plate, and so on.
✓As this process continues down the stack, the same volume of air is forced to travel through successively smaller
perforations, and so the air speed is progressively increased.
✓The progressively increased air speed lower down the column raises the momentum of the air-borne particles, so that even
the very smallest particles (less than 3 micrometres diameter) can impact onto the lower agar plates.
✓When the sampler has run for 5-15 minutes or more, the metal plates are separated and the Petri dishes are removed for
incubation to identify the colonies that develop.
ANDERSONSAMPLER

29. ❖BioaerosolSamplerisacosteffective,multi-stage,multi-orificecascadeimpactorthatmeasures
concentrationandparticlesizedistributionofaerosol-typebacteriaandfungiintheambientair.
❖Basedontheinertialimpactionprinciple,thesixstageviableimpactorcollectsallparticles,regardlessof
physicalsize,shape,ordensity.
❖Theparticlesareaerodynamicallysizedinwhichthereisadirectrelationshiptothepenetrationofthe
lung.
❖TheAndersenSixStageViableImpactorhasanaluminiuminletcone,sixaluminiumjetstages,glassPetri
dishes,andanaluminiumbaseplateheldtogetherbythreespringclampsandsealedwitho-ringgaskets.
❖Eachstagehas400precisionmachinedjetorifices.
❖TheSixStageImpactorhasacorrosionresistantbodyandoperatesataflowrateofexactly28.3lpm(1
CFM).
❖TheSixStageSamplerensureseaseofoperation:calibration,sterilisation,andsetup
ANDERSONSAMPLER

30. ANDERSONSAMPLER

31. ANDERSONSAMPLER

32. ANDERSONSAMPLER
https://www.youtube.com/watch?v=thiKRrXzp6o
https://www.youtube.com/watch?v=SxLoqO8jL4I

33. Thecollectionandassessmentofaerosolsamplesisquitesimple:Petridishescontaininganagarmediumare
placedintheinstrumentandthesampleofairisdrawninwhichthecorrespondingparticulatesarecollectedat
eachstageontheagarmedium.ThePetridishesarethenremoved,incubatedandcountedbyanaccepted
method.
APPLICATIONS
•Ambient Air Studies
•Indoor Air Studies
•Hospital & O.R. environments
•Virology investigations(including Influenza and SARS)
•Pharmaceutical production
•Filter and clean room efficiency studies
•Composting
•Wastewater treatment plants

34. ➢TheBurkardSporeTrap(Burkard)isavolumetricairsamplerthatisoneofthestandard
devicesformonitoringairbornepollenandspores.
➢Itiswidelyusedbytheallergycommunityandalsotheplantpathologycommunity.
➢TheBurkardisasuctionslitimpactorusedforpollenandsporesampling.
➢Thefirstsamplerofthistypewasdesignedin1952byDr.JamesHirstaplantpathologist.
➢Asaresult,samplersofthistypeareoftenreferredtoasaHirstsporetrap.Inadditionto
theBurkard,theLanzonisamplerandothersarealsobasedontheHirstdesign.
THEBURKARDSPORETRAP

35. •IntheBurkard,airisdrawnintoa14mmx2mmorificeat10literperminute,and
anyairborneparticleswithsufficientinertiaareimpactedoneitheragreasedtapeora
greasedmicroscopeslidebeneaththeorifice.
•Theimpactionsurfacemovespasttheorificeat2mmperhourpermittingtime-
discriminateanalysis.
•Thereisalsoawindvaneattachedtothesamplerhead;sincetheheadisabletorotate
theorificeisalwaysorientedintothewind.
•ThestandardorificeontheBurkardsamplerisefficientforparticlesdownto3.7µm;
thismeansthatallbutthesmallestsporeswillbeefficientlytrapped.
THEBURKARDSPORETRAP

36. THEBURKARDSPORETRAP
•TheBurkardsporesampleractsonthesameprincipleastherotorodsampler,butisused
togiveacontinuousrecordofparticlesintheairoveraperiodof24hoursorupto7
days.
•Theapparatusconsistsofanair-sealeddrumthatcontainsaclockworkrotatingdisc
whichmakesasinglerevolutionin7days.
•Thesurfaceofthisdisciscoveredwithadhesivetape,totrapsporesthatimpactontoit.
•Whentheapparatusisassembled,airissuckedintothedrumathighspeedthroughaslit
orificebymeansofamotoratthebaseoftheapparatus.

37. ❑Anyparticlesintheairimpactontothestickytapeneartheslitorifice,givingarecordof
theparticlesintheatmosphereataspecifictimeofday.
❑Attheendofa7-dayrun,thetapeisremoved,cutintosectionsrepresentinghourlyor
dailyperiods,thenexaminedmicroscopicallyforcountingandidentificationofpollenand
spores.
❑Inthisway,itispossibletodistinguishclearlybetweennight-releasedandday-released
sporesorotherparticles,andalsotorelatethetypesofparticletodifferentweather
conditions(e.g.humidordryperiods)whiletheapparatuswasrunning.
❑TheBurkardsporetrapiscommonlyusedforcontinuousmonitoringofsporeorpollen
loadsintheair.
THEBURKARDSPORETRAP

38. THEBURKARDSPORETRAP

39. ❖Impingersusealiquidmediumforparticlecollection.
❖Typically,sampledairisdrawnbyasuctionpumpthroughanarrowinlettubeintoasmallflaskcontainingthecollection
medium.
❖Thisacceleratestheairtowardsthesurfaceofthecollectionmediumandtheflowrateisdeterminedbythediameterof
theinlettube.
❖Whentheairhitsthesurfaceoftheliquid,itchangesdirectionabruptlyandanysuspendedparticlesareimpingedintothe
collectionliquid.
IMPINGERS

40. Oncethesamplingiscompletethecollectionliquidcanbeculturedtoenumerateviablemicroorganisms.Sincethe
samplevolumecanbecalculatedusingtheflowrateandsamplingtime,theresultisquantitative.
•GlassImpingershavegraduationsin5mlincrementsandavailablewithafrittednozzletoincreasecontactbetween
theairsampleandtheliquid.
•PFAimpingersareunbreakable,inerttovirtuallyallchemicalsandperformwellinhightemperatureandcryogenic
applications.
IMPINGERS
Glass Impingers PFA impingers

41. Thesamplingairbubblesthroughanozzleplateintoan
extractionliquidsuchasdistilledwater.Theairborne
particlesaretransportedintotheliquidduringthebubble
formation,releaseandrise.

42. •This is a means of sampling replacing the solid sorbent tube with a liquid.
•Impingers have a tapered outlet which allows particulate matter to exit at high velocity, hit the flask
bottom and be captured in solution.
•Bubblers are open or fritted to increase the surface area so the gases are absorbed into solution. This is a
preferred method.
•Impingers and bubblers can be positioned in an area, held or mounted in a holster.
Here is a typical sample train for an impinger/bubbler:
•After sampling the tubes or the sampled liquid are sealed and sent off to a laboratory for further analysis.
•The sorbent tubes are desorbed either chemically or thermally and for an impinger/bubbler, the sampled
liquid is analysed, generally by Gas chromatography.
ANALYSIS OF SAMPLE